There was a succession of missed late opportunities at the Principality Stadium last night but Ireland's latest Six Nations disappointment really swung away from them in the ten minutes before half time.
Nursing a slender 6-5 lead, and having first seized control of the encounter through some monstrous hits and shuddering carries, Wales - predictably - roared back into contention, gaining oxygen in the stifling environment after repelling a series of Irish attacks.
George North had already breached Ireland's try line once when he powerfully rumbled towards the 22 after 32 minutes, with scrum-half Conor Murray - one of the most proficient and fearless defenders in his position - forced to stop the big wing.
Murray, as usual, fulfilled his brief, but it came at a huge cost - the figurative loss of an arm.
The star number nine wasn't of a mind to leave the field, and nobody thought to take the choice out of his hands.
Speaking on RTE at half time, former Ireland boss Eddie O'Sullivan said that Murray staying on the field was a 'medical decision, not a coaching decision'.
Such logic is beyond faulty in this case. Murray is obviously, along with his half-back partner Johnny Sexton, one of Ireland's two most important players. However, he ceases to be in any way influential if he can no longer perform his primary duty: pass the ball.
Joe Schmidt often bristles at criticism of his side, batting it away by saying that it is merely external noise from people who don't have the full facts.
This was one case where you didn't need heaps of statistics, just a set of working eyes, to assess the damage. Murray's passes were noticeably wobbling after the knock, and as the game crept towards half time it became more and more of an issue.
Tadhg Furlong will cop the majority of the blame for the knock on in the build-up to Wales' go-ahead penalty and Sexton's yellow card. But in re-watching the handling error, it is obvious that Murray's pass - while not overly unsympathetic - isn't delivered with the crispness that his forwards are accustomed to.
Those few minutes were extremely costly for Ireland - they never retook the lead and lost their playmaker for a very costly ten minutes, with North crossing for a second try while Sexton watched on from the sideline.
Schmidt and the medical team obviously felt that Murray had recovered sufficiently over the half time break to keep going - that he was finally replaced five minutes later highlighted the folly of their initial decision to keep him on.
Murray was gone by the time Sexton rejoined the fray, with the performance of Kieran Marmion off the bench making Schmidt's decision to leave his crocked starter in the game all the more baffling.
Working off static ball, Marmion's delivery was sharp, and just like when he deputised on the wing in November, he put his body on a big Welsh ball carrier to snuff out the threat of a try.
One of Schmidt's key goals between the 2015 and 2019 World Cups was to build enough depth so that Ireland could withstand a similar injury barrage to the one that derailed them against Argentina.
How do you think Marmion felt watching from the bench as a one-armed Murray contributed to a laboured attack in the closing moments of the first period, despite good field position?
The injury hampered his delivery and although Murray was blameless for Heaslip's sloppy dropped ball to end the half, a fit Marmion would surely have sparked a more meaningful attack.
Schmidt defended his decision to leave Murray in the game in the post-match press conference, saying that he 'got a stinger and the shoulder improved sufficiently at half-time and he felt he could probably have played on. But his passing wasn’t as sharp as normal, there was a 15% or so deficiency so we thought it was better for him to come off. He was keen to stay on'.
This is when the coaching staff needs to step in and put the interests of the team above the player. Murray is good enough that he should generally be given the benefit of the doubt, but when such an integral part of his game is compromised, it hurts the team to leave him in the fray.
By the time he finally made way, Ireland were in a nine point hole that they never recovered from.
Chance after chance was missed to close the gap, but perhaps if more assertive action had been taken after Murray's collision with North, the need for a late try wouldn't have been so great.
The Left Wing
Luke Fitzgerald has called on Joe Schmidt to bring Peter O'Mahony into the Irish starting team for next weekend's final Six Nations clash against England at the Aviva Stadium.